Ultrasound has been used to observe lung aeration and fluid clearance during the neonatal transition period, but there is no consensus regarding optimal timing of ultrasound. We aimed monitor trend serial ultrasound score (LUS) extended LUS (eLUS) throughout period (≤1, 2, 4, 8, 24, 48 h after birth), assess any correlation clinical presentation (using Silverman Andersen Respiratory Severity Sc...